A dzo (also spelled zo, zho and dzho, Standard Tibetan: མཛོ་, romanized: mdzo) is a hybrid between the yak and domestic cattle. The word dzo technically refers to a male hybrid, while a female is known as a dzomo or zhom. In Mongolian, it is called a khainag (хайнаг). There is also the English language portmanteau term of yattle, a combination of the words yak and cattle,[1] as well as yakow,[2][3] a combination of the words yak and cow.
Dzomo are fertile (or, fecund) while dzo are sterile. As they are a product of the hybrid genetic phenomenon of heterosis (hybrid vigor), they are larger and stronger than yak or cattle from the region.[4] In Mongolia and Tibet, khainags are thought to be more productive than cattle or yaks in terms of both milk and meat production.[5][6]
Dzomo can be back crossed. As a result, many supposedly pure yak or pure cattle probably carry each other's genetic material. In Mongolia, the result of a khainag crossed with either a domestic bull or yak bull is called ortoom (ортоом, three-quarter-bred) and an ortoom crossed with a domestic bull or yak bull results in a usan güzee (усан гүзээ, one-eighth-bred).[6][7]
Dzos inherit two distinct protein types, one from each parent, leading to alterations in their mitochondrial structure and function.[8] Consequently, this adaptation significantly enhances the dzo's capacity to thrive at higher altitudes compared to either parent.
^Mummolo, Jonathan (August 11, 2007). "Yattle What?". The Washington Post. Retrieved January 3, 2017. Mentzer, who grew up farming in Loudoun County, and his partner, Jim Dumbrell, a retired British oil and gas pipeline consultant, are breeding yattle -- a cross between cows and yaks.
^Long, L., Zhu, Y., Li, Z., Zhang, H., Liu, L., & Bai, J. (2020). Differential expression of skeletal muscle mitochondrial proteins in yak, dzo, and cattle: a proteomics-based study. The Journal of veterinary medical science, 82(8), 1178–1186. https://doi.org/10.1292/jvms.19-0218
